Is there a site that's reliable at telling who's in the meta?

I'm starting to feel like I'm being held back my champion pool, so I want to try and expand it but I don't want to waste time on champs that aren't doing good. I'm looking for more mid laners. If anyone knows who is in the meta for mid or a site that is reliable at telegraphing this information, I would much appreciate being told. Also, I normally check champion.gg, metaLoL, nerfplz and a couple others but not as often, but they all contradict each other some what often.